Method for forming concrete box culverts and the like

ABSTRACT

Construction of a box culvert on an already-poured concrete base which includes a concrete riser at each edge thereof and studs encased in the base under the risers which extend horizontally outwardly therefrom by securing vertical wall forms to such studs so that the wall forms extend upwardly from the outer edges of the risers, connecting the upper edges of the wall forms together at their top by a longitudinal member of adjustable length, rolling interior mold apparatus between the risers and the vertical wall forms, such apparatus having vertical beams carrying vertical interior forms, the vertical beams being connected by expansible rods which force the interior vertical wall forms against the inner edges of the risers into an opposed relationship with the outer vertical wall forms, providing expansible rods connected to the vertical beams so as to maintain them and also the interior vertical wall forms in rigid parallel relationship, securing the outer vertical wall forms and the interior vertical wall forms together at their edges, securing a ceiling form across the upper edges of the interior vertical forms, pouring concrete into the space defined by the outer vertical wall forms and the interior mold apparatus to form the walls and top of the culvert, and when the concrete is sufficiently hardened, removing the forms by increasing the length of the longitudinal member securing the outer wall forms together, contracting the rods connecting the interior wall forms and moving the forms to the next station along the base to repeat the process.

United States Patent Holland [54] METHOD FOR FORMING CONCRETE BOXCULVERTS AND THE LIKE [72] Inventor: Harry L. Holland, 1215 Park Hill 1Drive, N.E., Gainesville, Ga. 30501 [22] Filed: May 4,1970

[21] Appl. No.: 4 8,792

Related U.S. Application Data [631' Continuation of Ser. No. 683,924,Nov. 17,

1967, abandoned.

521 U.S. c1. ..264/32, 249/11, 249/22,

[51] Int. Cl. ..E04b 1/32, E04g 11/34 [58] Field of Search ..249/10, 11,12, 22, 27, 29, 249/30, 209; 25/128 D, 128 K, 131.5 D,

Primary Examiner-Robert F. White Assistant Examiner-Jan H. SilbaughAttorneyMason, Mason & Albright 1 51 Oct. 3, 1972 [57] ABSTRACTConstruction of a box culvert on an already-poured concrete base whichincludes a concrete riser at each edge thereof and studs encased in'thebase under the risers which extend horizontally outwardly therefrom bysecuring vertical wall forms to such studs so that the wall forms extendupwardly from the outer edges of the risers, connecting the upper edgesof the wall forms together at their top by a longitudinal member ofadjustable length, rolling interior mold apparatus between the risersand the vertical wall forms, such apparatus having vertical beamscarrying vertical interior forms, the vertical beams being connected byexpansible rods which force the interior vertical wall forms against theinner edges of the risers into an opposed relationship with the outervertical wall forms, providing expansible rods connected to the verticalbeams so as to maintain them and also the interior vertical wall formsin rigid parallel relationship, securing the outer vertical wall formsand the interior vertical wall forms together at their edges, securing aceiling form across the upper edges of the interior vertical forms,pouring concrete into the space defined by the outer vertical wall formsand the interior mold apparatus to form the walls and top of theculvert, and when the concrete is sufficiently hardened, removing theforms by increasing the length of the longitudinal member securing theouter wall forms together, contracting the rods connecting the interiorwall forms and moving the forms to the next station along the base torepeat the process.

S CIaims, 5 Drawing Figures can PATENTEDnm 3 I972 SHEET 1 BF 2 lll INVENT OR HARRY HOLLAND ATTORNEYS METHOD FOR FORMING CONCRETE BOX CULVERTSAND THE LIKE This application is a continuation of Ser. No. 683,924,filed Nov. 17, 1967, and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to a method for thepositioning of mold parts to receive concrete in the production ofculverts and the like and the apparatus utilized for this purpose. Moreparticularly, the invention concerns exterior and interior mold partswhich cooperate with an already poured base having concrete risers ateither end so that the mold parts can be rapidly positioned prior topouring the concrete and removed after the concrete has been hardened.

The box culvert is, at least in this country, perhaps the most commontype of poured concrete culvert. The box culvert design permits theaccurate positioning of the reinforcement rods without having to conformsame to special shapes. It is generally strong, provides ample space forthe flow of water, is adaptable to roadways, and is reasonablyeconomical of material cost for the results obtained. However, at leastuntil the introduction of my invention, there have been no generallyaccepted significant changes in methods of constructing such culverts.As a rule, the forms were affixed in place by standard carpentryprocedure; that is,

in the contemporary process, large inside and outside wall forms,together with top forms, are nailed together at the site for theculvert. The outer wall forms are generally braced or otherwise urgedagainst the edges of the risers of the base and the inner moldapparatus, generally plywood mold parts, are nailed to the outer moldpart or otherwise braced by carpentry to remain in position whenconcrete is poured. The plywood mold pieces used in such constructionlast, on the average, to pours. The instant inventor was coinventor fora method and apparatus (U. S. Pat. No. 3,277,556) which relatesprimarily to the positioning of molds and reinforcement rods in theconstruction of the base por tion of the culvert. The method andapparatus disclosed therein is utilized to construct the concrete basefor the invention, although it will be understood that conventionalmethods may also be used for this purpose if desired.

A problem with contemporary methods is the necess ity that aboutone-half of the crew consist of skilled labor. A further problem is thatmolding apparatus suggested by the prior art has generally been limitedto a particular construction and is not practical for the variety ofspecifications which exist in the normal construction businesses becauseof inventory costs.

vThe inventor has ascertained that his invention permits a labor costreduction of about forty per cent, drastically reduces the skilled laborrequirement, pro vides that the forms will outlast by many times formsused in conventional methods, and gives a cleaner and smoother concretefinish than is provided by prior art conventional construction methods.Moreover, the invention may be applied to a broad choice of sizeswithout requiring the practitioner of the invention to inventory anunduly large number of mold parts.

SUMMARY OF THE INVENTION The invention in this case provides substantialsavings and improves the construction of box culverts. Whereas oneskilled in the art might give more weight to one aspect of the inventionthan to others, the inventor considers that there are two components ofspecial importance. The first of these lies in the threaded studs whichare initially embedded in the concrete base and provide an effective andefficient means of supporting and positioning the outer wall forms inthe correct, rigid relationship with the concrete base. The secondcomponent is the connection members for the interior mold apparatuswhich cooperate with other elements to provide a strong and convenientmeans for anchoring the interior mold apparatus in a correct rigidrelationship with the concrete base. These components, in theirrelationship with the other elements such as the adjustable fasteningmeans which secures the tops of the outer molds together, assist greatlyto make the method and apparatus as a whole a practical and commerciallyacceptable improvement for normal culvert construction operations.

Other objects, adaptabilities and capabilities will appear as thedescription progresses, reference being had to the accompanying drawingsin which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric viewillustrating the components of the invention about an already-pouredsection of box culvert;

FIG. 2 is an elevational view showing the invention;

FIG. 3 is a fragmentary perspective view of the connection between theinterior expansible members and the upright beams which carry theinterior mold;

FIG. 4 is a fragmentary sectional top view of the connection shown inFIG. 3; and

FIG. 5 is a fragmentary side elevation showing a barrier mold in placeon the open end of the mold.

DESCRIPTION OF THE PREFERRED EMBODIMENT After the necessary excavation,grading and preparation of underlying earth is completed, a concretebase 10 is laid with each edge including a riser 11, which is on theright, and 12, on the left, as seen in FIG. 2. Preferably the concretebase 10 is formed in accordance with the method set forth in U. S. Pat.No. 3,277,556. Inasmuch as various means for constructing a base 10 arewell known, it is, however, not considered necessary to describe same indetail to impart an understanding of the instant invention to a personskilled in the art. In forming the base 10, however, a plurality ofthreaded studs are secured to extend outwardly from both sides of thebase 10 under the risers 11 and 12. The threaded studs may, if desired,be carried by jack nuts 15 which are completely encased in the concrete.The studs 14 are aligned with care at, say, 8 inches under the top ofthe riser and spaced a predetermined distance apart, say 56 inches, toreceive the vertical exterior beams 16 which carry the vertical moldforms 17. A standard length mold form is 16 feet and thus, with thestuds 14 spaced 56 inches apart, 1 foot is provided between the edge ofthe mold form 17 and the stud 14 on each end.

The widths and heights of box culverts are generally specified by evenfeet. With knowledge of the specified height and width for a culvertsunderpass, an interior mold apparatus designated generally is fashionedabout interior steel bracing designated generally 21. The bracing 21comprises a plurality of vertical steel beams 22 with a fasteningstructure 24 welded thereto. As shown in detail in FIGS. 3 and 4, thefastening structure 24 comprises a U-shaped bracket 25 which is weldedto the beam 22 and provides a space 26 at the side of beam 22 facingtowards the center of base 10. A slot 27 is also provided in the spacedportion of the bracket 25. The space 26 together with the slot 27 isadapted snugly to receive the flanged part 30 and the tube portion 31,which is rigidly affixed to part 30. In order to provide the entirestructure with rigidity, it is important that in the manufacture of thefastening structure 24, the tolerances be such that flange part 30 fitssnugly although removably within the space 26.

Flange part 30 and tube part 31 are components of an expansible meansdesignated generally 32 which also includes a joint 34 which rigidlyconnects tube part 31 to a further tube part 35 through flanges withbolts or other appropriate securing means. Extending from tube part 35on the end away from joint 34 is a threaded rod 36 which receives aturnbuckle 37 which is, in turn, threadably received on its other end bya further rod 38 terminating in a flange part 30 snugly received bybracket 25.

As will be understood by reference to FIG. 2, a plurality of interiorsteel bracing parts 21 have secured thereto the interior wall forms 40.Each wall form 40 includes a plurality of ribs 41 rigidly securedthereto by bolts, nails or other appropriate means. Forms 40 are,through plates 42 and 44, affixed to the vertical beams 22 In FIGS. 1and 2 it will be noted that the vertical beams are each mounted oncasters 43 which are turnable so that the interior steel bracing may bemoved as desired along the upper surface of the base 10. The wall forms40 are situated on beams 22 to overlap risers l1 and 12. Thus, if therisers are, say, 6 inches in height, the wall forms 40 may be, say, 4inches from the base 10. When the interior steel bracing 21 with wallforms 40 is to be placed into its desired position, turnbuckle 37 isadjusted so that the distance between wall forms 40 is somewhat lessthan the distance between the risers 11 and 12. Upon bringing theinterior steel bracing 21 into its desired location along base 10,shimming boards 48 are placed under the wall forms 40 which are raisedslightly in the process, and the tumbuckles 37 are adjusted to force thelower portions of wall forms 40 against adjacent risers l1 and 12 and toinsure that the wall forms 40 are vertically disposed. When sopositioned, horizontal ceiling forms 46 are laid over the upper ends ofthe vertical beams 22 so that their biased edges 50 are received betweenthe upper ends of the wall forms 40. The ceiling forms 46 also include aplurality of horizontal ribs 47. Boards 51 may be provided to extendlongitudinally with reference to the culvert for the purpose of engagingthe ends of the beams 22 and to bear forms 46 through ribs 47. A tightfit of the ceiling form 46 is insured by the inward adjustment of theupper expansible means 32 through its turnbuckle 37. The edges 50 havesufficient give that they can be moved towards each other a slight butsignificant distance. Turnbuckle 37 should not be tightened at thispoint to such an extent as to preclude further inward movement after theconcrete has hardened.

From foregoing description it will be understood that the interior moldapparatus is braced rigidly in place with the lower expansible means 32being generally in compressive stress urging the vertical beams 22apart,whereas the upper expansible means 32 is in tension to provide atight relationship between the horizontal ceiling forms 46 and interiorwall forms 40.

With the interior mold apparatus 20 now in place, the exterior moldforms 17 having beams 16 secured thereto are maneuvered to receivethreaded studs 14 in apertures 52 located in the lower portions of thebeams 16. Wing nuts 54 are threadably received by the threaded studs 14whereby they urge vertical beams 16 towards base 10. As was noted withreference to the interior wall forms 40, the exterior vertical moldforms 17 overlap the risers 11 and 12 and are thus urged against suchrisers through the agency of the wing nuts 54. The external verticalmold forms 17 include a plurality of horizontal ribs 55 which areaffixed thereto. Beams 16 have welded or otherwise secured theretoplates 56 which carry forms 17, such forms being attached to plates 56by nails or other securing means.

Disposed above the interior mold apparatus 20 and connecting to theupper ends of beams 16 are adjustable fastening members 60. Thesefastening members 60 are connected to beams 16 by a steel pin or bolt 61which is received in one of the spaced horizontal apertures 62. Eachmember 60 comprises tube portions 64 and 65, which include the apertures62. Oppositely threaded rods 66 and 67 which extend from the tubeportions 64 and 65, respectively, are received by turnbuckle member 70.By properly selecting apertures 62 for the bolts 61 and adjusting thedistance between the vertical beam 16 by means of turnbuckle 70, beams16 and therefore forms 17 may be brought into vertical alignment.

In order to space the reinforcement rods 71 correctly with reference toforms 17 and 40, a plurality of spacers 72 known as highchairs arepositioned to engage the reinforcement rods 71 and bear against theforms 17 and 40, as shown in FIG. 2. It has been found that thesehighchairs 72 frequently need not be nailed to the forms, whereby asmoother wall results. In the event, however, that the spacers fail tobe brought against the forms, the threepenny nail is ample to secure thehighchair to the adjacent form. The horizontal reinforcement rods 74 aresimilarly spaced from the horizontal mold 46 by means of a plurality ofhighchairs 75. As desired, further reinforcement rods may be similarlypositioned relative to the forms.

An end barrier 80, illustrated in FIG. 5, may be secured by C-clamps 81or other appropriate means across an open end or ends of the mold. Insuch case, in order to promote rigidity of the mold, the barrier mayalso be nailed to ribs 41 of the interior mold apparatus 20.Alternatively, where other barrier means are provided, wood struts 84may be nailed across the forms 17 and 40 for the purpose of maintainingthe wall thickness when the pouring of concrete takes place.

With end barriers 80 or other appropriate barriers in place, the pouringis normally accomplished by first pouring concrete to about one-third ofthe height on one side and then pouring tw0-thirds of the height on theother side, followed by completely filling the first poured side, nextthe other side, and then the top area. Finally, the concrete ispermitted to harden in a normal manner.

After the concrete has hardened to the point that the molds may beremoved, the vertical wall forms 17 are easily loosened by turningturnbuckles 70 so as to extend the adjustable fastening members 60. Wingnuts 54 and bolts 61 are removed and the forms 17 can then be readilytake to the next section or from the area. The interior mold apparatus20 is removed by removing shim boards 48, taking up on the upper andlower turnbuckles 37, and simply rolling the interior steel bracing 21together with the interior wall molds 40 from under the concrete boxculvert. As the vertical beams 22 are moved, the horizontal ceilingforms 46, if not already loosened, tend to loosen of their own weightand may be readily removed. The threaded studs 14 are screwed out of thejack nuts or otherwise removed from the base 10. The holes which areleft are filled with concrete after the operation is completed.

The expansible means 32 can be lengthened or shortened, if desired, bymerely inserting different lengths of a further tube part 35. Also, inorder to construct culverts of a number of different sizes, it isnecessary to have steel vertical beams 22 of various lengths andhorizontal ceiling forms 46 to correspond to various widths of theculvert opening. Otherwise, the same components can be used forconstructing many different sizes of box culverts.

The above description and drawings disclose the preferred embodiments ofmy invention, but it is to be understood that it is capable of otheradaptations and modifications within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A method of forming a concrete box culvert which comprises the stepsof: pouring a concrete base so that it includes at opposite sides a pairof parallel risers having vertical side walls with the outboard walls ofsaid risers extending vertically from a height below the surface of thebasebetween said risers; causing to be embedded a plurality of parallelstuds within the said base so as to extend horizontally and normallyfrom the outboard walls under the level of said base surface 5 justablyfastening the upper end of said wall forms together by an adjustablefastening means; introducing an interior mold means between said risers,said interior mold means including a pair of vertical forms, ahorizontal ceiling form, and horizontal extensible means connecting saidpair of vertical forms; expanding said vertical forms of said interiormold means by horizontally lengthening said extensible means against theinboard of said vertical sidewalls of said risers so that a pair ofvertically extending channels are formed by said vertical forms of saidinterior mold means and said wall forms which channels are uninterruptedby any mold apparatus for maintaining said interior mold means and saidwall forms in rigid relationship; pouring sufficient concrete into saidchannels to fill them and to cover said interior mold means whilemaintaining said wall forms and said interior mold means in a rigidrelationship by said adjustable fastening means and said extensiblemeans; permitting the concrete to harden in the normal manner; andremoving said wall forms by horizontally extending said adjustablefastening means, and lowering said interior mold means and drawing saidvertical forms of interior mold means together by horizontallyshortening said extensible means for the removal of same.

2. A method in accordance with claim 1 wherein reinforcement rods riseout of said risers, which includes the step of placing highchairsbetween said reinforcement rods and said wall forms whereby saidreinforcement rods are spaced by the dimensions of said highchairs awayfrom said reinforcement rods.

3. A method in accordance'with claim 1 which includes the additionalstep of removing said studs from said concrete base after the verticalwall forms have been removed therefrom and filling the holes left bysaid studs with concrete.

4. A method in accordance with claim 1 wherein said interior mold meansand exterior wall forms are secured together prior to pouring concretein said

1. A method of forming a concrete box culvert which comprises the stepsof: pouring a concrete base so that it includes at opposite sides a pairof parallel risers having vertical side walls with the outboard walls ofsaid risers extending vertically from a height below the surface of thebase between said risers; causing to be embedded a plurality of parallelstuds within the said base so as to extend horizontally and normallyfrom the outboard walls under the level of said base surface betweensaid risers; securing a pair of vertical wall forms to said studswhereby said wall forms are supported by said studs, urging said wallforms against the upper sides of the vertical sidewalls of said risers;adjustably fastening the upper end of said wall forms together by anadjustable fastening means; introducing an interior mold means betweensaid risers, said interior mold means including a pair of verticalforms, a horizontal ceiling form, and horizontal extensible meansconnecting said pair of vertical forms; expanding said vertical forms ofsaid interior mold means by horizontally lengthening said extensiblemeans against the inboard of said vertical sidewalls of said risers sothat a pair of vertically extending channels are formed by said verticalforms of said interior mold means and said wall forms which channels areuninterrupted by any mold apparatus for maintaining said interior moldmeans and said wall forms in rigid relationship; pouring sufficientconcrete into said channels to fill them and to cover said interior moldmeans while maintaining said wall forms and said interior mold means ina rigid relationship by said adjustable fastening means and saidextensible means; permitting the concrete to harden in the normalmanner; and removing said wall forms by horizontally extending saidadjustable fastening means, and lowering said interior mold means anddrawing said vertical forms of interior mold means together byhorizontally shortening said extensible means for the removal of same.2. A method in accordance with claim 1 wherein reinforcement rods riseout of said risers, which includes the step of placing highchairsbetween said reinforcement rods and said wall forms whereby saidreinforcement rods are spaced by the dimensions of said highchairs awayfrom said reinforcement rods.
 3. A method in accordance with claim 1which includes the additional step of removing said studs from saidconcrete base after the vertical walL forms have been removed therefromand filling the holes left by said studs with concrete.
 4. A method inaccordance with claim 1 wherein said interior mold means and exteriorwall forms are secured together prior to pouring concrete in saidchannels.
 5. A method in accordance with claim 1 wherein said verticalwall forms are urged inwardly against said ceiling form.